A fluid nozzle is a device used to accelerate and exhaust a fluid as a jet. The nozzle is usually a converging area duct which forces the fluid passing through the duct to increase in velocity and decrease in pressure. The nozzle creates a thrust force on the device the flow is exiting from; for example, a nozzle on a jet engine is used to generate thrust for the engine. The fluid exhaust jet produced by the same nozzle generates an impact force on any object it strikes. Fluid nozzles are used on compressed air shop guns to generate a high velocity jet to move shop debris. Similarly, nozzles on leaf blowers use the exiting jet to move leaves. Numerous other devices use a nozzle to generate a high momentum, fluid jet to transmit a force to an object that is a distance away from the nozzle exit.
If a jet of fluid is directed through a nozzle and into a reservoir of external still (ambient) fluid, the jet path is straight and the streamlines become parallel. This must be true because any turning, divergence, or velocity change of the jet would require a corresponding static pressure change which cannot exist in the still fluid. The friction between the moving jet and the ambient fluid causes the outer edges of the jet to be slowed down and the external fluid to be speeded up, or entrained. Thus, the jet rapidly mixes out and the jet velocity decreases with distance as presented in FIG. 1, labeled “Prior Art.” Speed and the Reynolds number have only slight effects until the fluid exit velocity of the nozzle approaches the speed of sound in the fluid. The edge mixing effects penetrate to the center of the jet within an axial distance of about 5 diameters downstream of the nozzle exit, and the jet peak velocity drops over 80% within 40 diameters. For a three-inch leaf blower nozzle, this results in at least an 80% decrease in jet impingement force available (when compared to the jet momentum at the nozzle exit) to move leaves a distance of 10 feet from the nozzle being held by the user of the leaf blower.
It is a primary object of the current invention to present a fluid nozzle system that combines a controlled flow pulse device with a toroidal exhaust generation device to create a self-propelling jet for a long-range impact, e.g., for particle movement.
It is another primary object to present a fluid nozzle system that combines a controlled flow pulse device with a toroidal exhaust generation device to create a jet that travels up to 10 times the distance of current continuous flow jets.
It is a more specific object, commensurate with the above-listed objects, to combine a controlled flow pulse device with a toroidal exhaust generation device that uses single or multi-stage ejectors to increase the momentum of the unsteady pulse flow before converting the pulse into a jet with higher impact forces and/or carrying capabilities than conventional, continuous flow jets.